GB594125A - Improvements in or relating to caliper and other gauges - Google Patents

Abstract

594,125. Gauges. HEARN, J. W. E., and OPTICAL MEASURING TOOLS, Ltd. June 16, 1944, No. 11546. [Class 106 (ii)] [Also in Group XX] In a gauge comprising a body portion adapted to be held in the hand, a measuring member urged by a spring into contact with the workpiece, and a graduated scale with a relatively movable index controlled by the measuring member, the body portion is provided with means for locking the measuring member against movement when removed from the workpiece and an optical magnifier for displaying the scale and index for direct inspection or by projection on a screen. A direct inspection gauge, Fig. 2, comprises a body portion which carries a pair of " not go " anvils (not shown) and a pair of " go " anvils 12, 16. The anvil 16 is arranged in a slot in the body and may be moved away from the anvil 12 against the action of spring 27. It may be locked in position by a device 28. Aligned apertures are provided in the anvil and the body to receive the optical system. The tube 24 arranged in the body contains the eye-piece 25 and a glass 26 engraved with a vernier. A graticule 19 in the anvil is engraved with a scale marked in thousandths of an inch. A condenser 21 is arranged in the body to convert into a parallel beam the light received through 'the aperture 23 in the shield 22. In the projection gauge, Fig. 4, the optical system also includes a lens 29 which forms an image of the graticule in the plane of the vernier. The gauge is located over an aperture in a table 30, Fig. 7, by a standard 31. When in position, the gauge closes a switch 37 to light a lamp 32 which sends a beam through the condenser 33 to project an image of the scale and vernier on to a screen 36.